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1. Field of the Invention
The invention relates generally to the field of signal processing. More particularly, the invention relates to a method and apparatus for filtering common mode interference.
2. Discussion of the Related Art
Typically, multi-channel navigation systems include an array of sensors (or transducers) and signal conditioning elements for detecting analog signals and generating digital data for further processing by a guidance processor. The guidance processor can determine the position of a signal source based on the received information while using parameters characteristic of the array. A multi-channel navigation system may be, for example, a multi-channel laser seeker.
A multi-channel laser seeker receives laser pulses on a few of its multiple channels, and uses this data to determine the direction or position of a laser source. In practice, the seeker receives data only on a small subset of its channels for any given laser pulse, while the other channels are near zero on their response.
Unfortunately, multi-channel laser seekers may be subject to electrical interference that may appear as large signals on most or all channels simultaneously. The electrical interference may be in the form of pulses and, when the average pulse repetition frequencies (PRF) is high, it may severely degrade the seeker's performance.